1. Field of the Invention
Aspects of the present invention relate to a power apparatus, a wireless communication apparatus having the same, and a power supplying method thereof, and more particularly, to a power apparatus, a wireless communication apparatus having the same, and a power supplying method thereof, which supplies power to the wireless communication apparatus in a switched mode.
2. Description of the Related Art
A wireless communication apparatus, such as a laptop computer and/or a mobile phone, performs wireless communication, such as digital multimedia broadcasting (DMB), high speed downlink packet access (HSDPA), and wireless broadband internet (WiBro) communication, to provide various functions. The wireless communication apparatus may include a switched-mode power apparatus, which is more efficient than a linear mode power apparatus, to receive operating power. FIG. 1 is a circuit diagram of a synchronous buck converter 1 as an example of a typical switched-mode power apparatus.
As shown therein, the synchronous buck converter 1 includes a control field-effect transistor (CFET) and a synchronous field-effect transistor (SFET) as paired switching elements, a filter inductor LF, and a filter capacitor CF. The synchronous buck converter 1 converts an input voltage VDC into an output voltage VOUT. In the switched-mode power apparatus of FIG. 1, the CFET and the SFET are alternately turned on and off according to a PWM (pulse width modulation) control signal with a predetermined dead time, which cause high frequency noises such as high frequency oscillation of a phase voltage VPHASE.
FIG. 2 illustrates a waveform of the high frequency noise. As shown therein, reference numerals 2 and 3 refer to PWM control signals which are respectively inputted to the CFET and the SFET. The reference numeral 4 is the phase voltage VPHASE applied across the SFET, while the reference numerals 5 and 6 respectively refer to the high frequency noise at a rising edge and a falling edge of the phase voltage VPHASE.
If the frequency of the high frequency noise is close to a frequency of a wireless communication signal of the wireless communication apparatus, the reception sensitivity of the wireless communication and/or the wireless communication apparatus is lowered due to interference between the high frequency noise and the wireless communication signal, to thereby deteriorate the quality of the wireless communication using the wireless communication signal.